Audio production for television, video, film, and recorded music sales is a large and growing enterprise, and is the foundation of much of the entertainment industry. Automation in the form of computerization is becoming more and more important as the basis of technical advances in this industry, to provide ability to mix and process more sophisticated and more voluminous audio input, and to provide more flexibility in output. Computerization is also seen as a requirement for cost-effective competition. Manual instruments, systems, and techniques are, by comparison, increasingly more expensive to use.
The basic instrument of audio production is the production mixing console, a workstation presenting an interface to a sound engineer through which he or she may condition multiple channels of audio input, and mix the conditioned results into mono or stereo outputs for direct broadcast or for recording. A production mixing console, hereinafter a mixer, typically presents arrays of input devices, such as switches, knobs, and "faders", for an operator to set to condition and route audio signals. A fader is typically a slide rheostat through which an amplitude may be adjusted as a result of the linear position of the input lever relative to a track.
Mixers typically route audio input signals to individual channels, and each such channel has a repetitive layout of switches, knobs, and faders. For example, a single channel can have more than one input, such as a microphone input and an input from an instrument, a group of instruments, or a tape. Using the controls on a mixer an engineer can select microphone, line, and tape inputs, route the inputs to signal conditioning devices like faders and equalizers, and mix and route the output from the conditioning devices as well. There is typically a selective ability to monitor audio signals, such as by headphones, and often a microphone for talkback by the sound engineer operating the console.
Audio mixing, especially with digital techniques and computer control, is historically a rather recent development. When rock-and-roll music was first introduced there was no such device as a mixer. In the fifties, recording was done by direct input. Modern mixing was initiated about the time of the appearance of the Beatles, and the first units were highly individualistic. Through the sixties and early seventies direct audio mixers continued to be developed, and continued to be relatively small units with a few channels and were very unique in layout. In the mid-seventies standards began to appear, especially relative to layout of switches, rotary potentiometers, and faders. With a standard layout it became possible for a sound engineer to go from one studio to another, and take over the functions comfortably.
In the early development and well into the late seventies, mixers were completely manual. The audio signals were routed to the mixer, and directly through the switches, pots, and faders. As a result, there were some definite limitations and problems. For example, with the audio signals routed directly through the switching and signal processing devices, it was necessary that heavy duty, low noise devices be developed. Without ultra-high quality devices, contacts, rheostat slides, and the like produce unwanted clicks and other noises that are incorporated into the audio signals.
Another difficulty is that the devices have to be used a great deal. During production sessions an engineer is constantly making changes in settings of many devices, and, just like any other expensive equipment, the mixer has to be used a great deal to justify its cost. Still another problem is that with audio signals routed through the console, especially in the event of many channels in use for multiple inputs, there is a lot of opportunity for cross-talk, meaning mixing of signals not meant to be mixed.
In addition to the problems described above, there are also particular limitations relative to manual consoles. One is simply size. As the number of inputs increases, the necessity for additional channels also increases, and the size of the console layout increases as well. Consoles quickly become unwieldy, and an engineer has to move up and down a wide console to make adjustments.
Yet another limitation is that manual settings have to be made for every session, and adjusted. It is quite difficult to duplicate favorite settings. An engineer using a manual console must make notes and diagrams of preferred settings, and adjust manual controls to suit. Even when settings are recorded, it is very difficult to reproduce them exactly on a single console, much less on a different console. With a manual console, sound engineering is very much an art and very little a science.
In the 1980's automation began to appear in professional recording studios. The first efforts were patchwork devices for automating manual console functions, and even today many automated consoles are analog audio consoles with digital equipment adapted to existing devices. Part of the reason for this is the expense of analog audio equipment, and the natural reluctance of manufacturers to Scrap usable and saleable devices in favor of complete new designs. So there has been a tendency to automate in an incremental fashion, leaving some functions manual, and in almost all cases, continuing to route audio signals through the console.
What is needed is a console designed to separate the audio from the control console, with all controlled audio routed and processed in a completely separate area. Such a system needs to be computer controlled and software based, "remembering" device settings for future use, and taking advantage of digital processing techniques, such as displaying equalizer curves and allowing software set up and configuration.